I can't live without some keyboard customizations. I open keyboard preferences, and get function keybindings to work without requiring the pressing of fn key. While there I map the CAPSLOCK to Control key. I use alt-left/right to traverse between desktops.

My Emacs customization takes some time. I use the modularized emacs24-starter kit at http://eschulte.github.io/emacs24-starter-kit/. It is great, it has good defaults, but it would be much better if it has better documentation and instructions.

Since I install emacs using cask rather than from binary, I get to enjoy good package-manager support using ELPA. To see the available packages type M-x package-show-package-list. I install auctex, exec-path-from-shell, ipython, magit, python-mode, tomatinho, visual-fill-column.

I use a wheat background, and Chalkboard font. (Update August'17: I switched to using Monaco font at 14 points.) I use highlight line mode as well with lightsteelblue1 color.